To resolve the issue of being unable to change the group category of an Active Directory group:
- Check that the domain controller of the domain you are attempting to modify the group on is operating normally.
- Verify that the user you are using to perform the changes has sufficient permissions for the change to complete.
- Confirm that any necessary prerequisites have been met to enable the change.
- Ensure that there are no group policy objects (GPOs) that are preventing the change.